The body count for African rhinos killed for their horns is approaching crisis proportions, according to the latest figures released by the International Union for Conservation of Nature (IUCN).

To National Geographic reporter Peter Gwin, the dire numbers—a rhinoceros slain every 11 minutes since the beginning of 2013—don't come as a surprise. "The killing will continue as long as criminal gangs know they can expect high profits for selling horns to Asian buyers," said Gwin, who wrote about the violent and illegal trade in rhino horn in the March 2012 issue of the magazine.

The recent surge in poaching has been fueled by a thriving market in Vietnam and China for rhino horn, used as a traditional medicine believed to cure everything from hangovers to cancer. Since 2011, at least 1,700 rhinos, or 7 percent of the total population, have been killed and their horns hacked off, according to the IUCN. More than two-thirds of the casualties occurred in South Africa, home to 73 percent of the world's wild rhinos. In Africa there are currently 5,055 black rhinos, listed as critically endangered by the IUCN, and 20,405 white rhinos. (From our blog: "South African Rhino Poaching Hits New High.")

Trying to snuff out poaching by itself won't work, said Gwin. The South African government is fighting a losing battle on the ground to gangs using helicopters, dart guns, high-powered weapons—and lots of money. (National Geographic pictures: The bloody poaching battle over rhino horn [contains graphic images].)

"Every year they get tougher on poaching, but rhino killings continue to rise astronomically," said Gwin. "Somehow they have to address the demand side in a meaningful way. This means either shutting down the Asian markets for rhino horn, or controversially, finding a way to sustainably harvest rhino horns, control their legal sale, and meet what appears to be a huge demand. Either will be a formidable endeavor."

Hope and Hurdles

The signing in December of a memorandum of understanding between South Africa and Vietnam to deal with rhino poaching and other conservation issues raises hope for some concrete action. Observers say the next step is for the two governments to follow through with tangible crime-stopping efforts such as intelligence sharing and other collaboration. The highest hurdle to stopping criminal trade, though, is cultural, Gwin believes. "In Vietnam and China, a lot of people simply believe that as a traditional cure, rhino horn works." (Related: "Blood Ivory.")

The recent climb in rhino deaths threatens what had been a conservation success story. Since 1995, due to better law enforcement, monitoring, and other actions, the overall rhino numbers have steadily risen. The poaching epidemic, the IUCN warns, could dramatically slow and possibly reverse population gains.

The population growth is also being stymied by South Africa's private game farmers, who breed rhinos for sport hunting and tourism and for many years have helped rebuild rhino numbers. Many of them are getting out of the business due to the high costs of security and other risks associated with the poaching invasions.

Those who still have rhinos on their farms will often pay a veterinarian to cut the horns off—under government supervision—to dissuade poachers, but the process costs more than $2,000 and has to be repeated when the horns grow back every two years. Even then the farmers are stuck with horns that are illegal to sell—and which criminals seek to obtain.

Room for Debate

Rhino killings and the trade in their horns will be a major topic at a high-profile conference, the 16th meeting of the Conference of the Parties to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which opens in Bangkok March 3. What won't surprise Gwin is if the issue of sustainably harvesting rhino horns from live animals comes up for discussion.

"It's an idea that seems to be gaining traction among some South African politicians and law enforcement circles," he said, noting that the international conservation community strongly opposes any talk of legalizing the trade of rhino horn, sustainably harvested or not. The bottom line for all parties in the discussion is clear, said Gwin: "The slaughter has to stop if rhinos are to survive."